Portable power bank



FIG. 1 is a front view of a portable power bank of my new design, according to a first embodiment;

FIG. 2 is a rear view thereof;

FIG. 3 is a right side view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a top view thereof;

FIG. 6 is a bottom view thereof;

FIG. 7 is a top, front, left side perspective view thereof;

FIG. 8 is a bottom, rear, right side perspective view thereof;

FIG. 9 is a front view of a portable power bank of my new design, according to a second embodiment;

FIG. 10 is a rear view thereof;

FIG. 11 is a right side view thereof;

FIG. 12 is a left side view thereof;

FIG. 13 is a top view thereof;

FIG. 14 is a bottom view thereof;

FIG. 15 is a top, front, left side perspective view thereof; and,

FIG. 16 is a bottom, rear, right side perspective view thereof.

The broken lines shown in the drawings illustrate portions of the portable power bank that form no part of the claimed design. 

CLAIM The ornamental design for a portable power bank, as shown and described. 